The present invention relates to a heat exchange process, preferably a cooling process intended to remove at least a part of the heat produced in at least one reaction and/or at least one purification operation involving hydrofluoric acid, especially anhydrous or substantially anhydrous hydrofluoric acid, the said cooling being performed by heat exchange with a cooling fluid maintained at a desired temperature and circulating in a circuit which comprises at least one exchange zone presenting a risk of leakage of hydrofluoric acid into the cooling fluid.
In a conventional cooling circuit employing water as cooling fluid, any leakage of hydrofluoric acid into the water gives rise locally, or in the whole system, to a highly corrosive situation, running the risk of endangering the life of the plant, before it has been possible to remedy the leakages. Even if the response is quick and the circuit is drained, dilute hydrofluoric acid may be trapped in regions which are difficult to purge.
The use of a nonaqueous fluid, such as oil or a Freon, instead of water, as cooling fluid, can be envisaged. The size of the exchangers then results in very high operating costs. Furthermore, in the case of leakage it becomes necessary to drain such a nonaqueous fluid containing hydrofluoric acid and there is no simple solution enabling such a fluid to be reemployed once it has been contaminated.